This invention relates to a power distribution assembly that utilizes multiple power and control modules that can be easily removed for repair or replacement without requiring removal of all modules.
Typically vehicles, such as an aircraft, utilize a secondary power distribution assembly (SPDA) to distribute power from a primary source to various aircraft systems. An SPDA includes a chassis that is mounted within the vehicle and which houses multiple power modules that are used to power the aircraft systems. These power modules can be solely DC modules, solely AC modules, or a combination of DC and AC modules installed within a common SPDA. Control modules are also housed within the SPDA, for functions such as communications, microprocessing, etc. The power modules interact with the control modules to provide proper communication and control of power for each of the aircraft systems.
Traditionally, a SPDA includes an internally mounted wiring harness for connecting multiple power cables from the various aircraft systems to the proper power module. Each different type of aircraft includes a specially designed SPDA that includes power modules that meet that aircraft""s predetermined specifications. Thus, each different SPDA requires a different wiring harness design and power module configuration, resulting in proliferation of components.
One disadvantage with previous SPDA designs is that a module is considered to be a shop replaceable unit (SRU), i.e., when a module fails, the entire SPDA must be removed from the aircraft in order to repair or replace the module. This repair is performed in a service shop. This requires disconnecting multiple aircraft systems when only one specific system""s module is inoperable. Once the defective module has been replaced, all of the modules within the SPDA must be reconnected to their respective systems with each connection requiring post-repair verification. This can involve testing thousands of connections resulting in significant time and labor costs.
It is desirable to provide an improved SPDA with modules that are line replaceable modules (LRMs) such that each module can be individually removed from the SPDA chassis without requiring removal of the SPDA from the aircraft or removal of other modules from the SPDA. It is also desirable to provide a common SPDA that can be used on different aircraft types. The SPDA should be able to utilize any combination of AC and/or DC power modules with separate AC and DC busses incorporated into the aircraft wiring harness in addition to overcoming the above referenced deficiencies with prior art systems
The subject invention provides a modular design for a power distribution assembly including a secondary power distribution assembly (SPDA). The SPDA includes AC and/or DC power modules and control modules that are installed within a vehicle mounted chassis. The modules can be individually and selectively removed from the chassis for repair or replacement without having to remove the entire SPDA from the aircraft. Further, modules can be grouped into families for installation into a specific vehicle type. Thus, a common SPDA can be used for all vehicle types by simply changing the power module family to meet the vehicle""s specifications.
Each power module includes a connector for attachment to an aircraft wiring harness and a control connector for attachment to a motherboard. The aircraft wiring harness is external to the SPDA and connects directly to the individual module wiring harness connector. The modules can be individually and selectively removed from the chassis for repair or replacement without having to remove the entire SPDA from the aircraft by simply removing the module from the chassis thereby, disconnecting the wiring harness and motherboard connectors for the selected modules. AC and/or DC modules can be used in a common SPDA and separate AC and DC buses are maintained.
The chassis includes a plurality of installation slots for receiving the modules. Typically, there are more installation slots than modules installed within the chassis such that multiple vehicle types can utilize a common SPDA. After each module is installed within a slot, a protective mounting plate is optionally installed over each module to enclose the module within the chassis. The mounting plate includes an identification portion for uniquely identifying the module covered by that plate.
In one embodiment, aircraft interface and control connectors are mounted to opposite ends of the power module. The aircraft interface connector has both power contacts and signal contacts. The power contacts provide a power feed to the power module and provide output power to loads requiring high current. The signal contacts provide output power to loads requiring low current and provide the configuration pins for the loads serviced by the respective module.
In another embodiment, aircraft interface and control connectors are mounted on a common end of the module. The aircraft interface and control connectors are simultaneously mated with the motherboard and aircraft wiring harness respectively when each of the power modules is installed within the chassis. The connectors are keyed to ensure the proper power module is being installed in each slot within the chassis.
In another embodiment, the chassis includes a control section and a power module section. The control section includes installation slots for receiving control modules and the power module section includes installation slots for receiving the power modules. In one orientation, the control module installation slots are transverse to the power module slots, while in an alternate orientation the control module and power module slots are parallel to each other.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.